rv_major_opcode_1010011.mdwn

   1 # Summary FP Opcodes
   2
   3 This page aids and assists in the development of FP proposals,
   4 by identifying and listing in full both publicly-known proposals
   5 and the full brownfield encoding space available in the 0b010011
   6 major opcode.
   7
   8 A primary critical use-case for extending FP is for 3D and supercomputing.
   9
  10 Publicly-known FP proposals:
  11
  12 * Zfrsqrt - Reciprocal SQRT <http://bugs.libre-riscv.org/show_bug.cgi?id=110>
  13 * Zftrans - Transcendentals (FSIN, FCOS, FATAN, FPOW, FEXP, FLOG, FRCP)
  14   <http://bugs.libre-riscv.org/show_bug.cgi?id=127>
  15 * Extension of formats to cover FP16 (RISC-V ISA Manual Table 11.3 "fmt field")
  16 * HI-half FP MV - <https://github.com/riscv/riscv-isa-manual/pull/301>
  17   <https://groups.google.com/a/groups.riscv.org/forum/m/#!topic/isa-dev/kXgfFqgBv-c>
  18 * (Add new entries here: Zextname - Description and URL)
  19
  20 [[!toc levels=2]]
  21
  22 # Main FP opcode 1010011 table
  23
  24 Notes:
  25
  26 * Proposed new encodings in **bold**.
  27 * *Use funct5 sparingly!* - 2-operand functions only.
  28 * Single-argument FP operations should go under one of the funct5 tables
  29 * Both dual and single argument FP operations that do not require
  30   "rounding mode" should go in one of the funct5 tables that already use
  31   "funct3".
  32 * Be careful not to use encoding space for which FP16 has already been
  33   reserved.
  34
  35 [[!table  data="""
  36 31..27  | 26..25  | 24..20 |19..15| 14...12| 11..7 | 6....0  | function    |
  37 funct5  | SDHQ    | rs2    | rs1  | funct3 | rd    | opcode  | name        |
  38  5      | 2       | 5      | 5    | 3      | 5     |   7     |             |
  39 00000   | xx      | rs2    | rs1  | rm     | rd    | 1010011 | FADD.xx     |
  40 00001   | xx      | rs2    | rs1  | rm     | rd    | 1010011 | FSUB.xx     |
  41 00010   | xx      | rs2    | rs1  | rm     | rd    | 1010011 | FMUL.xx     |
  42 00011   | xx      | rs2    | rs1  | rm     | rd    | 1010011 | FDIV.xx     |
  43 00100   | xx      | rs2    | rs1  | yyy    | rd    | 1010011 | ?           |
  44 00101   | xx      | rs2    | rs1  | yyy    | rd    | 1010011 | tb=00101    |
  45 00110   | xx      | rs2    | rs1  | yyy    | rd    | 1010011 | ?           |
  46 00111   | xx      | rs2    | rs1  | yyy    | rd    | 1010011 | ?           |
  47 01000   | xx      | rs2    | rs1  | yyy    | rd    | 1010011 | tb=01000    |
  48 01001   | xx      | rs2    | rs1  | yyy    | rd    | 1010011 | ?           |
  49 01010   | xx      | rs2    | rs1  | yyy    | rd    | 1010011 | ?           |
  50 01011   | xx      | xxxxx  | rs1  | yyy    | rd    | 1010011 | tb=01011    |
  51 01100   | xx      | rs2    | rs1  | yyy    | rd    | 1010011 | ?           |
  52 01101   | xx      | rs2    | rs1  | yyy    | rd    | 1010011 | ?           |
  53 01110   | xx      | rs2    | rs1  | yyy    | rd    | 1010011 | ?           |
  54 01111   | xx      | rs2    | rs1  | yyy    | rd    | 1010011 | **FPOW.xx** |
  55 10000   | xx      | rs2    | rs1  | yyy    | rd    | 1010011 | ?           |
  56 10001   | xx      | rs2    | rs1  | yyy    | rd    | 1010011 | ?           |
  57 10010   | xx      | rs2    | rs1  | yyy    | rd    | 1010011 | ?           |
  58 10011   | xx      | rs2    | rs1  | yyy    | rd    | 1010011 | ?           |
  59 10100   | xx      | rs2    | rs1  | yyy    | rd    | 1010011 | tb=10100    |
  60 10101   | xx      | rs2    | rs1  | yyy    | rd    | 1010011 | ?           |
  61 10110   | xx      | rs2    | rs1  | yyy    | rd    | 1010011 | ?           |
  62 10111   | xx      | rs2    | rs1  | yyy    | rd    | 1010011 | ?           |
  63 11000   | xx      | xxxxx  | rs1  | yyy    | rd    | 1010011 | tb=11000    |
  64 11001   | xx      | rs2    | rs1  | yyy    | rd    | 1010011 | ?           |
  65 11010   | xx      | xxxxx  | rs1  | yyy    | rd    | 1010011 | tb=11010    |
  66 11100   | xx      | xxxxx  | rs1  | 000    | rd    | 1010011 | tb=11100    |
  67 11101   | xx      | rs2    | rs1  | yyy    | rd    | 1010011 | ?           |
  68 11110   | xx      | xxxxx  | rs1  | 000    | rd    | 1010011 | tb=11110    |
  69 11111   | xx      | rs2    | rs1  | yyy    | rd    | 1010011 | ?           |
  70 """]]
  71
  72 ## funct5 = 00000 - FADD
  73
  74 No brownfield encodings available.
  75
  76 ## funct5 = 00001 - FSUB
  77
  78 No brownfield encodings available.
  79
  80 ## funct5 = 00010 - FMUL
  81
  82 No brownfield encodings available.
  83
  84 ## funct5 = 00011 - FDIV
  85
  86 No brownfield encodings available.
  87
  88 ## funct5 = 00100 - unused
  89
  90 Brownfield encodings available.
  91
  92 ## funct5 = 00100
  93
  94 This table uses funct3 for encoding 2-operand FP operations
  95
  96 [[!table  data="""
  97 31..27  | 26..25  | 24..20 |19..15| 14...12| 11..7 | 6....0  | function    |
  98 funct5  | SDHQ    | rs2    | rs1  | funct3 | rd    | opcode  | name        |
  99  5      | 2       | 5      | 5    | 3      | 5     |   7     |             |
 100 00100   | xx      | rs2    | rs1  | 000    | rd    | 1010011 | FSGNJ.xx    |
 101 00100   | xx      | rs2    | rs1  | 001    | rd    | 1010011 | FSGNJN.xx   |
 102 00100   | xx      | rs2    | rs1  | 010    | rd    | 1010011 | FSGNJX.xx   |
 103 00100   | xx      | rs2    | rs1  | 011    | rd    | 1010011 | ?f3=011     |
 104 00100   | xx      | rs2    | rs1  | 100    | rd    | 1010011 | ?f3=100     |
 105 00100   | xx      | rs2    | rs1  | 101    | rd    | 1010011 | ?f3=101     |
 106 00100   | xx      | rs2    | rs1  | 110    | rd    | 1010011 | ?f3=110     |
 107 00100   | xx      | rs2    | rs1  | 111    | rd    | 1010011 | ?f3=111     |
 108 """]]
 109
 110 ## funct5 = 00101
 111
 112 This table uses funct3 for encoding 2-operand FP operations where the result
 113 register is a **floating-point** value.
 114
 115 [[!table  data="""
 116 31..27  | 26..25  | 24..20 |19..15| 14...12| 11..7 | 6....0  | function    |
 117 funct5  | SDHQ    | rs2    | rs1  | funct3 | rd    | opcode  | name        |
 118  5      | 2       | 5      | 5    | 3      | 5     |   7     |             |
 119 00101   | xx      | rs2    | rs1  | 000    | rd    | 1010011 | FMIN.S      |
 120 00101   | xx      | rs2    | rs1  | 001    | rd    | 1010011 | FMAX.S      |
 121 00101   | xx      | rs2    | rs1  | 010    | rd    | 1010011 | ?f3=010     |
 122 00101   | xx      | rs2    | rs1  | 011    | rd    | 1010011 | ?f3=011     |
 123 00101   | xx      | rs2    | rs1  | 100    | rd    | 1010011 | ?f3=100     |
 124 00101   | xx      | rs2    | rs1  | 101    | rd    | 1010011 | ?f3=101     |
 125 00101   | xx      | rs2    | rs1  | 110    | rd    | 1010011 | ?f3=110     |
 126 00101   | xx      | rs2    | rs1  | 111    | rd    | 1010011 | ?f3=111     |
 127 """]]
 128
 129 ## funct5 = 00110 - unused
 130
 131 Brownfield encodings available.
 132
 133 ## funct5 = 00111 - unused
 134
 135 Brownfield encodings available.
 136
 137 ## funct5 = 01000
 138
 139 This table uses rs2 for encoding 1-operand FP operations, using
 140 funct3 to specify the "rounding" mode
 141
 142 Notes:
 143
 144 * FP16 logically deduced from fmt field encoding (bits 25-26)
 145
 146 [[!table  data="""
 147 31..27  | 26..25  | 24..20 |19..15| 14...12| 11..7 | 6....0  | function    |
 148 funct5  | SDHQ    | rs2    | rs1  | funct3 | rd    | opcode  | name        |
 149  5      | 2       | 5      | 5    | 3      | 5     |   7     |             |
 150 01000   | 00      | 00000  | rs1  | rm     | rd    | 1010011 | ????????    |
 151 01000   | 00      | 00001  | rs1  | rm     | rd    | 1010011 | FCVT.S.D    |
 152 01000   | 00      | 00010  | rs1  | rm     | rd    | 1010011 | **FCVT.S.H**|
 153 01000   | 00      | 00011  | rs1  | rm     | rd    | 1010011 | FCVT.S.Q    |
 154 01000   | 00      | xxxxx  | rs1  | rm     | rd    | 1010011 | rs2?        |
 155 ------  | -----   | -----  | -----| -----  | ----- | ------- | --------    |
 156 01000   | 01      | 00000  | rs1  | rm     | rd    | 1010011 | FCVT.D.S    |
 157 01000   | 01      | 00001  | rs1  | rm     | rd    | 1010011 | ????????    |
 158 01000   | 01      | 00010  | rs1  | rm     | rd    | 1010011 | **FCVT.D.H**|
 159 01000   | 01      | 00011  | rs1  | rm     | rd    | 1010011 | FCVT.D.Q    |
 160 01000   | 01      | xxxxx  | rs1  | rm     | rd    | 1010011 | rs2?        |
 161 ------  | -----   | -----  | -----| -----  | ----- | ------- | --------    |
 162 01000   | 10      | 00000  | rs1  | rm     | rd    | 1010011 | FCVT.H.S    |
 163 01000   | 10      | 00001  | rs1  | rm     | rd    | 1010011 | **FCVT.H.D**|
 164 01000   | 10      | 00010  | rs1  | rm     | rd    | 1010011 | ????????    |
 165 01000   | 10      | 00011  | rs1  | rm     | rd    | 1010011 | FCVT.H.Q    |
 166 01000   | 10      | xxxxx  | rs1  | rm     | rd    | 1010011 | rs2?        |
 167 ------  | -----   | -----  | -----| -----  | ----- | ------- | --------    |
 168 01000   | 11      | 00000  | rs1  | rm     | rd    | 1010011 | FCVT.Q.S    |
 169 01000   | 11      | 00001  | rs1  | rm     | rd    | 1010011 | FCVT.Q.D    |
 170 01000   | 11      | 00010  | rs1  | rm     | rd    | 1010011 | **FCVT.Q.H**|
 171 01000   | 11      | 00011  | rs1  | rm     | rd    | 1010011 | ????????    |
 172 01000   | 11      | xxxxx  | rs1  | rm     | rd    | 1010011 | rs2?        |
 173 """]]
 174
 175 ## funct5 = 01001 - unused
 176
 177 Brownfield encodings available.
 178
 179 ## funct5 = 01010 - unused
 180
 181 Brownfield encodings available.
 182
 183 ## funct5 = 01011 - 1-op Transcendentals <a name="transcendentals_1op"></a>
 184
 185 This table uses rs2 for encoding 1-operand FP operations, using
 186 funct3 to specify the "rounding" mode
 187
 188 [[!table  data="""
 189 31..27  | 26..25  | 24..20 |19..15| 14...12| 11..7 | 6....0  | function      |
 190 funct5  | SDHQ    | rs2    | rs1  | funct3 | rd    | opcode  | name          |
 191  5      | 2       | 5      | 5    | 3      | 5     |   7     |               |
 192 01011   | xx      | 00000  | rs1  | rm     | rd    | 1010011 | FSQRT.xx      |
 193 01011   | xx      | 00001  | rs1  | rm     | rd    | 1010011 | **FRSQRT.xx** |
 194 01011   | xx      | 00010  | rs1  | rm     | rd    | 1010011 | **FRCP.xx**   |
 195 01011   | xx      | 00011  | rs1  | rm     | rd    | 1010011 | **CBRT.xx**   |
 196 01011   | xx      | 00100  | rs1  | rm     | rd    | 1010011 | ?             |
 197 01011   | xx      | 00101  | rs1  | rm     | rd    | 1010011 | ?             |
 198 01011   | xx      | 00110  | rs1  | rm     | rd    | 1010011 | ?             |
 199 01011   | xx      | 00111  | rs1  | rm     | rd    | 1010011 | ?             |
 200 01011   | xx      | 01000  | rs1  | rm     | rd    | 1010011 | **FEXP2.xx**  |
 201 01011   | xx      | 01001  | rs1  | rm     | rd    | 1010011 | **FLOG2.xx**  |
 202 01011   | xx      | 01010  | rs1  | rm     | rd    | 1010011 | **FEXPM1.xx** |
 203 01011   | xx      | 01011  | rs1  | rm     | rd    | 1010011 | **FLOGP1.xx** |
 204 01011   | xx      | 01100  | rs1  | rm     | rd    | 1010011 | **FEXP.xx**   |
 205 01011   | xx      | 01101  | rs1  | rm     | rd    | 1010011 | **FLOG.xx**   |
 206 01011   | xx      | 01110  | rs1  | rm     | rd    | 1010011 | **FEXP10.xx** |
 207 01011   | xx      | 01111  | rs1  | rm     | rd    | 1010011 | **FLOG10.xx** |
 208 01011   | xx      | 10000  | rs1  | rm     | rd    | 1010011 | **FSIN.xx**   |
 209 01011   | xx      | 10001  | rs1  | rm     | rd    | 1010011 | **FCOS.xx**   |
 210 01011   | xx      | 10010  | rs1  | rm     | rd    | 1010011 | **FTAN.xx**   |
 211 01011   | xx      | 10011  | rs1  | rm     | rd    | 1010011 | **FTAN2.xx**  |
 212 01011   | xx      | 10100  | rs1  | rm     | rd    | 1010011 | **FSINPI.xx** |
 213 01011   | xx      | 10101  | rs1  | rm     | rd    | 1010011 | **FCOSPI.xx** |
 214 01011   | xx      | 10110  | rs1  | rm     | rd    | 1010011 | **FTANPI.xx** |
 215 01011   | xx      | 10111  | rs1  | rm     | rd    | 1010011 | **FATAN2PI.xx**|
 216 01011   | xx      | 11000  | rs1  | rm     | rd    | 1010011 | **FSINH.xx**  |
 217 01011   | xx      | 11001  | rs1  | rm     | rd    | 1010011 | **FCOSH.xx**  |
 218 01011   | xx      | 11010  | rs1  | rm     | rd    | 1010011 | **FTANH.xx**  |
 219 01011   | xx      | 11011  | rs1  | rm     | rd    | 1010011 | ?             |
 220 01011   | xx      | 11100  | rs1  | rm     | rd    | 1010011 | **FASINH.xx** |
 221 01011   | xx      | 11101  | rs1  | rm     | rd    | 1010011 | **FACOSH.xx** |
 222 01011   | xx      | 11110  | rs1  | rm     | rd    | 1010011 | **FATANH.xx** |
 223 01011   | xx      | 11111  | rs1  | rm     | rd    | 1010011 | ?             |
 224 """]]
 225
 226 ## funct5 = 01100 - unused
 227
 228 Brownfield encodings available.
 229
 230 ## funct5 = 01101 - unused
 231
 232 Brownfield encodings available.
 233
 234 ## funct5 = 01110 - unused
 235
 236 Brownfield encodings available.
 237
 238 ## funct5 = 01111 - **FPOW**
 239
 240 Proposed for Zftrans - FPOW: "FP rs2 to the power of rs1"
 241
 242 ## funct5 = 10000 - unused
 243
 244 Brownfield encodings available.
 245
 246 ## funct5 = 10001 - unused
 247
 248 Brownfield encodings available.
 249
 250 ## funct5 = 10010 - unused
 251
 252 Brownfield encodings available.
 253
 254 ## funct5 = 10011 - unused
 255
 256 Brownfield encodings available.
 257
 258 ## funct5 = 10100
 259
 260 This table uses funct3 for encoding 2-operand FP "comparison" operations
 261 where the result register is an **integer**
 262
 263 Notes:
 264
 265 * FNE missing?
 266
 267 [[!table  data="""
 268 31..27  | 26..25  | 24..20 |19..15| 14...12| 11..7 | 6....0  | function    |
 269 funct5  | SDHQ    | rs2    | rs1  | funct3 | rd    | opcode  | name        |
 270  5      | 2       | 5      | 5    | 3      | 5     |   7     |             |
 271 10100   | xx      | rs2    | rs1  | 000    | rd    | 1010011 | FLE.xx      |
 272 10100   | xx      | rs2    | rs1  | 001    | rd    | 1010011 | FLT.xx      |
 273 10100   | xx      | rs2    | rs1  | 010    | rd    | 1010011 | FEQ.xx      |
 274 10100   | xx      | rs2    | rs1  | 011    | rd    | 1010011 | ?f3=011     |
 275 10100   | xx      | rs2    | rs1  | 100    | rd    | 1010011 | ?f3=100     |
 276 10100   | xx      | rs2    | rs1  | 101    | rd    | 1010011 | ?f3=101     |
 277 10100   | xx      | rs2    | rs1  | 110    | rd    | 1010011 | ?f3=110     |
 278 10100   | xx      | rs2    | rs1  | 111    | rd    | 1010011 | ?f3=111     |
 279 """]]
 280
 281 ## funct5 = 10101 - unused
 282
 283 Brownfield encodings available.
 284
 285 ## funct5 = 10110 - unused
 286
 287 Brownfield encodings available.
 288
 289 ## funct5 = 10111 - unused
 290
 291 Brownfield encodings available.
 292
 293 ## funct5 = 11000
 294
 295 This table uses rs2 for encoding 1-operand FP operations, using
 296 funct3 to specify the "rounding" mode
 297
 298 Notes:
 299
 300 * FP16 logically deduced from fmt field (bits 25-26)
 301
 302 [[!table  data="""
 303 31..27  | 26..25  | 24..20 |19..15| 14...12| 11..7 | 6....0  | function    |
 304 funct5  | SDHQ    | rs2    | rs1  | funct3 | rd    | opcode  | name        |
 305  5      | 2       | 5      | 5    | 3      | 5     |   7     |             |
 306 11000   | 00      | 00000  | rs1  | rm     | rd    | 1010011 | FCVT.W.S    |
 307 11000   | 00      | 00001  | rs1  | rm     | rd    | 1010011 | FCVT.WU.S   |
 308 11000   | 00      | 00010  | rs1  | rm     | rd    | 1010011 | FCVT.L.S    |
 309 11000   | 00      | 00011  | rs1  | rm     | rd    | 1010011 | FCVT.LU.S   |
 310 11000   | 00      | xxxxx  | rs1  | rm     | rd    | 1010011 | rs2?        |
 311 ------  | -----   | -----  | -----| -----  | ----- | ------- | --------    |
 312 11000   | 01      | 00000  | rs1  | rm     | rd    | 1010011 | FCVT.W.D    |
 313 11000   | 01      | 00001  | rs1  | rm     | rd    | 1010011 | FCVT.WU.D   |
 314 11000   | 01      | 00010  | rs1  | rm     | rd    | 1010011 | FCVT.L.D    |
 315 11000   | 01      | 00011  | rs1  | rm     | rd    | 1010011 | FCVT.LU.D   |
 316 11000   | 01      | xxxxx  | rs1  | rm     | rd    | 1010011 | rs2?        |
 317 ------  | -----   | -----  | -----| -----  | ----- | ------- | --------    |
 318 11000   | 10      | 00000  | rs1  | rm     | rd    | 1010011 |**FCVT.W.H** |
 319 11000   | 10      | 00001  | rs1  | rm     | rd    | 1010011 |**FCVT.WU.H**|
 320 11000   | 10      | 00010  | rs1  | rm     | rd    | 1010011 |**FCVT.L.H** |
 321 11000   | 10      | 00011  | rs1  | rm     | rd    | 1010011 |**FCVT.LU.H**|
 322 11000   | 10      | xxxxx  | rs1  | rm     | rd    | 1010011 | rs2?        |
 323 ------  | -----   | -----  | -----| -----  | ----- | ------- | --------    |
 324 11000   | 11      | 00000  | rs1  | rm     | rd    | 1010011 | FCVT.W.Q    |
 325 11000   | 11      | 00001  | rs1  | rm     | rd    | 1010011 | FCVT.WU.Q   |
 326 11000   | 11      | 00010  | rs1  | rm     | rd    | 1010011 | FCVT.L.Q    |
 327 11000   | 11      | 00011  | rs1  | rm     | rd    | 1010011 | FCVT.LU.Q   |
 328 11000   | 11      | xxxxx  | rs1  | rm     | rd    | 1010011 | rs2?        |
 329 """]]
 330
 331 ## funct5 = 11001 - unused
 332
 333 Brownfield encodings available.
 334
 335 ## funct5 = 11010
 336
 337 This table uses rs2 for encoding 1-operand FP operations, using
 338 funct3 to specify the "rounding" mode
 339
 340 * FP16 logically deduced from fmt field (bits 25-26)
 341
 342 [[!table  data="""
 343 31..27  | 26..25  | 24..20 |19..15| 14...12| 11..7 | 6....0  | function    |
 344 funct5  | SDHQ    | rs2    | rs1  | funct3 | rd    | opcode  | name        |
 345  5      | 2       | 5      | 5    | 3      | 5     |   7     |             |
 346 11010   | 00      | 00000  | rs1  | rm     | rd    | 1010011 | FCVT.S.W    |
 347 11010   | 00      | 00001  | rs1  | rm     | rd    | 1010011 | FCVT.S.WU   |
 348 11010   | 00      | 00010  | rs1  | rm     | rd    | 1010011 | FCVT.S.L    |
 349 11010   | 00      | 00011  | rs1  | rm     | rd    | 1010011 | FCVT.S.LU   |
 350 11010   | 00      | xxxxx  | rs1  | rm     | rd    | 1010011 | rs2?        |
 351 ------  | -----   | -----  | -----| -----  | ----- | ------- | --------    |
 352 11010   | 01      | 00000  | rs1  | rm     | rd    | 1010011 | FCVT.D.W    |
 353 11010   | 01      | 00001  | rs1  | rm     | rd    | 1010011 | FCVT.D.WU   |
 354 11010   | 01      | 00010  | rs1  | rm     | rd    | 1010011 | FCVT.D.L    |
 355 11010   | 01      | 00011  | rs1  | rm     | rd    | 1010011 | FCVT.D.LU   |
 356 11010   | 01      | xxxxx  | rs1  | rm     | rd    | 1010011 | rs2?        |
 357 ------  | -----   | -----  | -----| -----  | ----- | ------- | --------    |
 358 11010   | 10      | 00000  | rs1  | rm     | rd    | 1010011 |**FCVT.H.W** |
 359 11010   | 10      | 00001  | rs1  | rm     | rd    | 1010011 |**FCVT.H.WU**|
 360 11010   | 10      | 00010  | rs1  | rm     | rd    | 1010011 |**FCVT.H.L** |
 361 11010   | 10      | 00011  | rs1  | rm     | rd    | 1010011 |**FCVT.H.LU**|
 362 11010   | 10      | xxxxx  | rs1  | rm     | rd    | 1010011 | rs2?        |
 363 ------  | -----   | -----  | -----| -----  | ----- | ------- | --------    |
 364 11010   | 11      | 00000  | rs1  | rm     | rd    | 1010011 | FCVT.Q.W    |
 365 11010   | 11      | 00001  | rs1  | rm     | rd    | 1010011 | FCVT.Q.WU   |
 366 11010   | 11      | 00010  | rs1  | rm     | rd    | 1010011 | FCVT.Q.L    |
 367 11010   | 11      | 00011  | rs1  | rm     | rd    | 1010011 | FCVT.Q.LU   |
 368 11010   | 11      | xxxxx  | rs1  | rm     | rd    | 1010011 | rs2?        |
 369 """]]
 370
 371 ## funct5 = 11100
 372
 373 This table uses *both* rs2 *and* funct3 for encoding 1-operand FP operations.
 374
 375 Notes:
 376
 377 * FMV.X.Q is missing (alias of FMVH.X.D if it existed)
 378 * FP16 logically deduced from fmt field (bits 25-26)
 379 * FMVH.X.HW (half-word) missing?
 380
 381 [[!table  data="""
 382 31..27| 26..25| 24..20 |19..15|14...12| 11..7 | 6....0  | function    |
 383 funct5| SDHQ  | rs2    | rs1  |funct3 | rd    | opcode  | name        |
 384  5    | 2     | 5      | 5    | 3     | 5     |   7     |             |
 385 11100 | 00    | 00000  | rs1  | 000   | rd    | 1010011 | FMV.X.W     |
 386 11100 | 00    | 00000  | rs1  | 001   | rd    | 1010011 | FCLASS.S    |
 387 11100 | 00    | xxxxx  | rs1  | yyy   | rd    | 1010011 | rs2? f3?    |
 388 ------| ----- | -----  | -----| ----- | ----- | ------- | --------    |
 389 11100 | 01    | 00000  | rs1  | 000   | rd    | 1010011 | FMV.X.D **FMVH.X.W** |
 390 11100 | 01    | 00000  | rs1  | 001   | rd    | 1010011 | FCLASS.D    |
 391 11100 | 01    | xxxxx  | rs1  | yyy   | rd    | 1010011 | rs2? f3?    |
 392 ------| ----- | -----  | -----| ----- | ----- | ------- | --------    |
 393 11100 | 10    | 00000  | rs1  | 000   | rd    | 1010011 |**FMV.X.H**  |
 394 11100 | 10    | 00000  | rs1  | 001   | rd    | 1010011 |**FCLASS.H** |
 395 11100 | 10    | xxxxx  | rs1  | yyy   | rd    | 1010011 | rs2? f3?    |
 396 ------| ----- | -----  | -----| ----- | ----- | ------- | --------    |
 397 11100 | 11    | 00000  | rs1  | 000   | rd    | 1010011 | **FMVH.X.D** |
 398 11100 | 11    | 00000  | rs1  | 001   | rd    | 1010011 | FCLASS.Q    |
 399 11100 | xx    | xxxxx  | rs1  | yyy   | rd    | 1010011 | rs2? f3?    |
 400 """]]
 401
 402 ## funct5 = 11101 - unused
 403
 404 Brownfield encodings available.
 405
 406 ## funct5 = 11110
 407
 408 This table uses *both* rs2 *and* funct3 for encoding 1-operand FP operations.
 409
 410 Notes:
 411
 412 * FMV.Q.X is missing (as is FMVH.D.X)
 413 * FMVH.W.X is missing (alias of FMV.D.X)
 414 * FP16 logically deduced from fmt field (bits 25-26)
 415 * FMVH.HW.X (half-word) missing?
 416
 417 [[!table  data="""
 418 31..27  | 26..25  | 24..20 |19..15| 14...12| 11..7 | 6....0  | function    |
 419 funct5  | SDHQ    | rs2    | rs1  | funct3 | rd    | opcode  | name        |
 420  5      | 2       | 5      | 5    | 3      | 5     |   7     |             |
 421 11110   | 00      | 00000  | rs1  | 000    | rd    | 1010011 | FMV.W.X     |
 422 11110   | 00      | xxxxx  | rs1  | yyy    | rd    | 1010011 | rs2? f3?    |
 423 ------  | -----   | -----  | -----| -----  | ----- | ------- | --------    |
 424 11110   | 01      | 00000  | rs1  | 000    | rd    | 1010011 | FMV.D.X     |
 425 11110   | 01      | xxxxx  | rs1  | yyy    | rd    | 1010011 | rs2? f3?    |
 426 ------  | -----   | -----  | -----| -----  | ----- | ------- | --------    |
 427 11110   | 10      | 00000  | rs1  | 000    | rd    | 1010011 |**FMV.H.X**  |
 428 11110   | 10      | xxxxx  | rs1  | yyy    | rd    | 1010011 | rs2? f3?    |
 429 ------  | -----   | -----  | -----| -----  | ----- | ------- | --------    |
 430 11110   | 11      | 00000  | rs1  | 000    | rd    | 1010011 | ?           |
 431 11110   | 11      | xxxxx  | rs1  | yyy    | rd    | 1010011 | rs2? f3?    |
 432 """]]
 433
 434 ## funct5 = 11111 - unused
 435
 436 Brownfield encodings available.
 437
 438 ## funct5 = ????? (table template)
 439
 440 This table acts as a cut/paste template for creating brownfield encodings
 441
 442 [[!table  data="""
 443 31..27  | 26..25  | 24..20 |19..15| 14...12| 11..7 | 6....0  | function    |
 444 funct5  | SDHQ    | rs2    | rs1  | funct3 | rd    | opcode  | name        |
 445  5      | 2       | 5      | 5    | 3      | 5     |   7     |             |
 446 ------  | -----   | -----  | -----| -----  | ----- | ------- | --------    |
 447 """]]
 448